Lance Formation - called Laramie Formation in the 1870s - South Dakota - Wyoming - US

The Lance Formation is dominated by rocks of a regressive sequence consisting of nonmarine coastal floodplain sandstones, mudstones and marls, with marginal marine sandstones and shales in its lower parts. The Late Cretaceous environment in Wyoming was a warm temperate to subtropical, seasonal floodplain on the west coast of the eastward-regressing intracratonic seaway.

The Lance Formation encompasses a farly short period of geologic time (approximately 1.5 million years) at the end of the Maastrichtian. It reaches more than 750m in thickness and is found troughout Wyoming. Although vertebrate fossils are known from11 counties in Wyoming (Breithaupt, 1985), the most abundant and diverse faunas in the Lance Formation are known from Niobrara (Hatcher et al., 1907; Estes, 1964; Clemens, 1964, 1966, 1973; Derstler, 1994 and Sweetwater (Breithaupt, 1982) counties.


Agathaumas sylvestris - Wyoming - Neoceratopia Nomina Dubia - Cretaceous Late Maastrichtian


Albertosaurus sarcophagus - Wyoming - Tyrannosaurinae Albertosaurini - Cretaceous Late Campanian Maastrichtian



Anatotitan copei - South Dakota - Hadrosaurinae Edmontosaurini - Cretaceous Late Maastrichtian



Anatotitan longiceps - Wyoming - Hadrosaurinae Edmontosaurini - Cretaceous Late Maastrichtian



Ankylosaurus magniventris - Wyoming - Ankylosauria Ankylosauridae - Cretaceous Late, Maastrichtian



Aublysodon mirandus - Wyoming - Tyrannosauria Tyrannosauridae - Cretaceous Late Campanian Maastrichtian



Bison alticornis - Wyoming - Neoceratopia Nomina Dubia - Cretaceous Late Maastrichtian



Claosaurus annectens - Wyoming - Hadrosaurinae Edmontosaurini - Cretaceous Late Maastrichtian



Denversaurus schlessmani - South Dakota - Ankylosauria Nodosauridae - Cretaceous Late Maastrichtian



Diceratops hatcheri - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Diceratus hatcheri - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Edmontonia sp (1) - Wyoming - Not considered dinosaur



Edmontonia sp (3) - Wyoming - Ankylosauria Nodosauridae - Cretaceous Late Maastrichtian



Edmontosaurus annectens - Wyoming - Hadrosaurinae Edmontosaurini - Cretaceous Late Maastrichtian



Edmontosaurus regalis - South Dakota, Wyoming - Hadrosaurinae Edmontosaurini - Cretaceous Late Maastrichtian



Laelaps cristatus - Wyoming - Incertae Sedis \\\"Carnosaurs\\\" Nomina Dubia - Cretaceous Late Maastrichtian



Leptoceratops gracilis - Wyoming - Neoceratopia Protoceratopidae - Cretaceous Late Maastrichtian



Nedoceratops hatcheri - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Ornithomimus sedens - Wyoming - Ornithomimosauria Nomina Dubia - Cretaceous Late Maastrichtian



Pachycephalosaurus wyomingensis - Wyoming - Pachycephalosauria Pachycephalosauridae - Cretaceous Late Maastrichtian



Palaeoscincus latus - Wyoming - Ankylosauria Nomina Dubia - Cretaceous Late Maastrichtian



Paronychodon lacustris - Wyoming - Troodontidae Nomina Dubia - Cretaceous Late Campanian Maastrichtian



Pectinodon bakkeri - Wyoming - Maniraptora Troodontidae - Cretaceous Late Campanian Maastrichtian



Potamornis skutchi ~/~ - Wyoming - Ornithurae [Hesperonithiformes] - Cretaceous Late Maastrichtian



Ricardoestesia isosceles - Wyoming - Tetanurae Coelurosauria - Cretaceous Late Campanian



Stenonychosaurus inequalis - Wyoming - Maniraptora Troodontidae - Cretaceous Late Campanian Maastrichtian



Sterrholophus flabellatus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Stygimoloch spinifer - Wyoming - Pachycephalosauria Pachycephalosauridae - Cretaceous Late Maastrichtian



Thescelosaurus neglectus - Wyoming - Ornithopoda Hypsilophodontidae - Cretaceous Late Campanian Maastrichtian



Thespesius occidentalis - South Dakota - Hadrosauridae Nomina Dubia - Cretaceous Late Maastrichtian



Torosaurus gladius - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Torosaurus latus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Trachodon longiceps - Wyoming - Hadrosaurinae Edmontosaurini- Cretaceous Late Maastrichtian



Triceratops brevicornus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops calicornis - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops elatus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops eurycephalus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops flabellatus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops hatcheri - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops horridus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops ingens - Wyoming - Neoceratopia Nomina Dubia - Cretaceous Late Maastrichtian



Triceratops obtusus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops prorsus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops serratus - Wyoming - Ceratopidae Chasmosaurinae - Cretaceous Late Maastrichtian



Triceratops sulcatus - Wyoming - Neoceratopia Nomina Dubia - Cretaceous Late Maastrichtian



Troodon formosus (= Pectinodon bakkeri, Stenonychosaurus inequalis, ?Saurornithoides sp.) - Wyoming - Maniraptora Troodontidae - Cretaceous Late Campanian Maastrichtian



Troodon wyomingensis - Wyoming - Pachycephalosauria Pachycephalosauridae - Cretaceous Late Maastrichtian



Tyrannosaurus rex - Wyoming - Tyrannosauria Tyrannosauridae - Cretaceous Late Maastrichtian



Diplodocid indet. - Wyoming (may not come from Lance Formation) - Sauropoda - Cretaceous Late Maastrichtian



?Chirostenotes sp. - Wyoming - Theropoda Elmisauridae - Cretaceous Late Maastrichtian



?Thescelosaurus sp. - Wyoming - Ornithopoda Hypsilophodontidae - Cretaceous Late Maastrichtian



?Velociraptor sp. - Wyoming - Theropoda Dromaeosauridae - Cretaceous Late Maastrichtian



?Lambeosaurus sp. - Wyoming - Ornithopoda Hadrosauridae - Cretaceous Late Maastrichtian



Albertosaurus sp. - Wyoming - Tyrannosauria Tyrannosauridae - Cretaceous Late Maastrichtian



Ankylosaurid indet. - Wyoming - Ankylosauria Ankylosauridae - Cretaceous Late Maastrichtian



cf. Pachycephalosaurus sp. - Wyoming - Pachycephalosauria Pachycephalosauridae - Cretaceous Late Maastrichtian



Dromaeosaurid indet. - Wyoming - Theropoda Dromaeosauridae - Cretaceous Late Maastrichtian



Dromaeosaurus sp. - Wyoming - Theropoda Dromaeosauridae - Cretaceous Late Maastrichtian



Hadrosaurid indet. - Wyoming - Ornithopoda Hadrosauridae - Cretaceous Late Maastrichtian



Nodosaurid indet. - Wyoming - Ankylosauria Nodosauridae - Cretaceous Late Maastrichtian



Ornithomimus sp. - Wyoming - Theropoda Ornithomimidae - Cretaceous Late Maastrichtian



Triceratops sp. - Wyoming - Ceratopia Ceratopidae - Cretaceous Late Maastrichtian



Tyrannosaurid indet. - Wyoming - Tyrannosauria Tyrannosauridae - Cretaceous Late Maastrichtian



Tyrannosaurus sp. - Wyoming - Tyrannosauria Tyrannosauridae - Cretaceous Late Maastrichtian